System for gas permeation testing

ABSTRACT

A system for measuring gas permeation through container walls is disclosed, wherein a pressure fluid is introduced into a container to be tested. Once the pressure fluid is introduced into the container, the pressure fluid is drawn out of the container and tested to determine the permeation characteristics of the container.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/722,278 filed on Sep. 30, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a container testing apparatus. Moreparticularly, the present invention relates to a system for measuringgas permeation through plastic container walls.

2. Description of the Prior Art

In the preservation of beverages which are liable to be affected byoxidation, there is a problem that the beverages are oxidized by a smallamount of oxygen present in a container used for storage. Therefore, itis of paramount importance to ascertain the oxygen permeationcharacteristics of the plastic containers to be used for the beveragestorage. In the prior art, the systems for testing oxygen permeationrequire that each time a container is placed on or removed from a systemfor gas permeation testing, the containers to be tested must be affixedonto flat plates which have soldered connections that must be screwedonto a mating fitting of an associated manifold. Frequently, testingerrors result, primarily from minute leakage around the fittings andcomponents. Problems further increase with repeated use of the fittings.

One solution is to replace the fittings more often and to moremeticulously affix the container to the flat plates to ensure a betterconnection. However, these options significantly increase the amount oftime between testing of containers while still allowing for testingerrors.

Those skilled in the art have continued to search for the solution ofhow to provide a practical testing system.

SUMMARY OF THE INVENTION

In order to solve the problem longstanding in the art, a simplified andimproved system for mounting and connecting materials and containers forpermeation testing has been surprisingly provided.

In one embodiment of the present invention, the system is constructed oftwo main components; namely, moveable sample plates to which thecontainers are affixed, and a permanently mounted manifold.

The aforementioned sample plate is provided with three components;namely, a support for a container to be tested; conduits through which agas may flow; and bushings to ensure proper alignment of the sampleplate with the manifold.

The manifold is provided with three components; namely, pins to ensureproper alignment with the bushings of the sample plate; conduits throughwhich a gas may flow to and from the container during testing; andgrooves around the conduits which retain seals.

It is an object of the present invention to produce a system formeasuring gas permeation through a plastic material of the type employedfor producing plastic containers.

It is a further object of the present invention to eliminate screw-typetubing connections from the system to allow for faster removal andexchange of samples for testing.

It is still a further object still a further object of the presentinvention to decrease the time required to conduct the testingprocedures.

Still another object another object of the invention is to improve thereliability of the seal between the sample plate and container byconstructing a mounting plate with a pocket that the container fits intobefore being attached with a suitable adhesive material.

Further objects and advantages of the invention will be apparent fromthe following description and appended claims, reference being made tothe accompanying drawings forming a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become readilyapparent to those skilled in the art from reading the followingdescription of the invention when considered in the light of theaccompanying drawings, in which:

FIGS. 1 a, 1 b, 1 c, and 1 d are, respectively, top plan, endelevational, front elevational, and perspective views of a sample plateembodying the features of the invention;

FIGS. 2 a, 2 b, 2 c, and 2 d are, respectively, top plan, endelevational, front elevational, and perspective views of a manifoldembodying the features of the invention; and

FIGS. 3 a, 3 b, 3 c, and 3 d are, respectively, end elevational, topplan, and front elevational views of a base plate embodying the featuresof the invention.

It is to be understood that the present invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments, and of being practiced or carried out in variousways within the scope of the appended claims. Also, it is to beunderstood that the phraseology and terminology employed herein is forthe purpose of description, and not of limitation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the accompanying drawings, there is shown components of asystem for mounting and connecting plastic material, such as used incontainers for permeation testing which embody the features of theinvention.

The system includes two main components; namely, moveable sample platesto which a container to be tested is affixed; and an associated manifoldsystem.

A bushing shown in FIG. 1 d is adapted to receive pins of an associatedmanifold 30 shown in FIG. 2 d. The elements may be suitably affixed tothe base plate 50 shown in FIGS. 3 a, 3 b, and 3 c by threadedfasteners, for example.

The sample plate 10 comprises a main body 12 having an annular recess 14for receiving the neck or finish of a plastic container to be tested.The recess 14 is defined by an annular shoulder 16. A coaxial recess 18is formed centrally of the annular shoulder 16. The open end of therecess 18 is defined by an upstanding annular 20. A conduit 22 is formedin the main body 12 to provide communication between a source ofpressure fluid and the interior of the container being tested.

Another conduit 24 is formed in the main body 12 to providecommunication with a return of the pressure fluid introduced through theconduit 22. A pair of spaced apart bushings 26, 28 is formed to extendinwardly of the main body 12 and receive cooperating locating pins, aswill be explained hereinafter.

FIGS. 2 a, 2 b, 2 c, and 2 d illustrate a manifold 30 which comprises amain body 32 having at least one conduit 34 to communicate with theinlet of the sample plate conduit 22 and a conduit 36 communicating withthe sample plate conduit 24, and coupling means including pins 38, 39for selectively coupling the sample plate 10 and the manifold 30.

Grooves may be circumscribed around the inlets and outlets of conduitsof the sample plate 10 and the manifold 30 to retain seals. The sealsare utilized to close the system when the sample plate 10 is inoperative position. The grooves circumscribed around the conduits arepreferably grooves adapted to retain o-ring seals.

Any suitable means of selectively coupling the sample plate 10 andmanifold 30 may be used. It has been found that satisfactory results maybe achieved by utilizing the spaced apart inwardly extending bushing 26,28 in the sample plate 10 to receive the corresponding respective pins38, 39 of the manifold 30. Manifold mold-style pins 38, 39 as shown inFIG. 2 d ensure proper alignment with sample plate mold-style bushings26, 28 as shown in FIG. 1 d.

The manifold 30 can be mounted to a base plate 50 as illustrated inFIGS. 3 a, 3 b, and 3 c. The base plate 50 serves as a support for theentire system. The manifold 30 is provided with spaced apart passagewaysor holes 40, 42 to receive suitable threaded fasteners. The threadedends of such fasteners are threadably received within internallythreaded holes 52, 53, respectively of the base plate 50 to assureproper alignment. A pair of spaced apart passageways or holes is formedin the base plate 50 to allow the passage of conduits communicating withthe manifold conduits 34, 36. In the embodiment illustrated, the baseplate 50 is adapted to accommodate a pair of manifolds 30. The pair ofmanifolds may be formed separately or may be formed as one integralunit. The sample plates 10 which are used with the pair of manifolds 30may also be formed separately or as one integral unit.

Once aligned, the sample plate 10 is connected with the manifold 30. Theconnection may be tightened to urge the sample plate 10 against o-ringsin the manifold 30. Compression of the sample plate 10 against theo-rings closes the conduit-container-manifold system.

The sample plate 10, manifold 30, and base plate 50 are preferablyconstructed of aluminum or other lightweight durable alloy. Lightweightcomponents are desired for easier portability of system components andto allow rapid exchange of sample plates during testing. However, thecomponents of the system may be constructed of any appropriate materialthat withstand system temperature, pressure, and use requirements.

The testing of a container typically involves the following steps.First, a container is placed on and secured to the mounting area of asample plate 10 with an epoxy resin or other suitable adhesive material.The sample plate 10 is selectively coupled to the manifold 30 which isalready attached to the base plate 50. The sample plate 10 is securelycompressed against the o-rings of the manifold 30 to close the system.Compression occurs by tightening the connection between the sample plate10 and the manifold 30 by any means, such as by clamping, for example.

Once the system is closed, the pressure fluid is allowed to flow throughinto the container through the manifold conduit 34 and the sample plateconduit 22. Favorable results have been found wherein the pressure fluidis pure nitrogen. Once the pressure fluid is introduced into thecontainer, it flows out of the container through the sample plateconduit 24 and the manifold conduit 36. Any gas which permeated throughthe container will also flow out of the container through the sampleplate conduit 24 and the manifold conduit 36 to the testing sensor.

A system described above for testing a container may also be used totest permeation characteristics of other materials, such as a film forexample. In this situation, the film is disposed on an open-endedcontainer (not shown) and sealed or otherwise connected to the containerso the flow of fluid around the film into the container is militatedagainst. The sample plate conduits 22, 24 described above are incommunication with the container. The pressure fluid is introduced intothe container and exposed to the inner side of the film. The outer sideof the film is exposed to atmosphere or a controlled environment. Gaswhich permeates through the film is picked up by the pressure fluid andtested to determine the permeation characteristics of the film.

In accordance with the provisions of the patent statutes, the presentinvention has been described in what is considered to represent itspreferred embodiment. However, it should be understood that theinvention can be practiced otherwise than as specifically illustratedand described without departing from its spirit or scope.

1. A system for gas permeation testing of plastic containers comprising:a sample plate for receiving a container to be tested, at least oneconduit having an outlet providing communication between a source ofpressure fluid and the interior of the container being tested and aninlet; and a manifold having at least one outlet provided to communicatewith the inlet of the sample plate conduit and an inlet communicatingwith the source of pressure fluid, and means for selectively couplingthe sample plate and the manifold.
 2. The system for gas permeationtesting in accordance with claim 1, wherein said sample plate includes arecess formed thereon for receiving the container to be tested.
 3. Thesystem for gas permeation testing in accordance with claim 1, whereinsaid sample plate includes a second conduit having an outlet providingcommunication between the source of pressure fluid and a testing sensorand an inlet communicating with the interior of the container beingtested.
 4. The system for gas permeation testing in accordance withclaim 1, wherein said sample plate includes a second conduit having anoutlet providing communication between the source of pressure fluid anda second conduit of said manifold and an inlet communicating with theinterior of the container being tested.
 5. The system for gas permeationtesting in accordance with claim 4, wherein the second conduit of saidmanifold includes an outlet providing communication between the sourceof pressure fluid and a testing sensor and an inlet communicating withthe second conduit of said sample plate.
 6. The system for gaspermeation testing in accordance with claim 1, wherein said manifold isadapted to be mounted to a base plate.
 7. The system for gas permeationtesting in accordance with claim 1, wherein said manifold includes apair of spaced apart pins which are received by a pair of spaced apartbushings formed in said sample plate.
 8. The system for gas permeationtesting in accordance with claim 1, wherein said sample plate includes asecond recess for receiving the container to be tested.
 9. A system forgas permeation testing of plastic containers comprising: a sample platehaving a recess for receiving a container to be tested, at least oneconduit having an outlet providing communication between a source ofpressure fluid and the interior of the container being tested and aninlet; and a manifold having at least one outlet provided to communicatewith the inlet of the sample plate conduit and an inlet communicatingwith the source of pressure fluid, and means for selectively couplingthe sample plate and the manifold.
 10. The system for gas permeationtesting in accordance with claim 9, wherein said sample plate includes asecond conduit having an outlet providing communication between thesource of pressure fluid and a testing sensor and an inlet communicatingwith the interior of the container being tested.
 11. The system for gaspermeation testing in accordance with claim 9, wherein said sample plateincludes a second conduit having an outlet providing communicationbetween the source of pressure fluid and a second conduit of saidmanifold and an inlet communicating with the interior of the containerbeing tested.
 12. The system for gas permeation testing in accordancewith claim 11, wherein the second conduit of said manifold includes anoutlet providing communication between the source of pressure fluid anda testing sensor and an inlet communicating with the second conduit ofsaid sample plate.
 13. The system for gas permeation testing inaccordance with claim 9, wherein said manifold is adapted to be mountedto a base plate.
 14. The system for gas permeation testing in accordancewith claim 9, wherein said manifold includes a pair of spaced apart pinswhich are received by a pair of spaced apart bushings formed in saidsample plate.
 15. The system for gas permeation testing in accordancewith claim 9, wherein said sample plate includes a second recess forreceiving the container to be tested.
 16. A system for gas permeationtesting of a material comprising: a sample plate including a containerfor receiving a material to be tested, at least one conduit having anoutlet providing communication between a source of pressure fluid and asurface of the material being tested and an inlet; and a manifold havingat least one outlet provided to communicate with the inlet of the sampleplate conduit and an inlet communicating with the source of pressurefluid, and means for selectively coupling the sample plate and themanifold.
 17. The system for gas permeation testing in accordance withclaim 16, wherein said sample plate includes a second conduit having anoutlet providing communication between the source of pressure fluid anda second conduit of said manifold and an inlet communicating with theinterior of the container being tested, the second conduit of saidmanifold including an outlet providing communication between the sourceof pressure fluid and a testing sensor and an inlet communicating withthe second conduit of said sample plate.
 18. The system for gaspermeation testing in accordance with claim 16, wherein said manifold isadapted to be mounted to a base plate.
 19. The system for gas permeationtesting in accordance with claim 16, wherein said manifold includes apair of spaced apart pins which are received by a pair of spaced apartbushings formed in said sample plate.
 20. The system for gas permeationtesting in accordance with claim 16, wherein said sample plate includesa second recess for receiving the container to be tested.